1. Field of the Invention
The present invention relates to a method and apparatus for container pattern-forming and palletizing the containers in predetermined patterns on pallets.
2. Description of the Prior Art
Containers or packages are commonly placed on pallets in order to facilitate their movement. In the art of palletizing containers, it is well known to arrange a plurality of containers into a layer and then sequentially stack the layer in tiers on a pallet. Sequential tiers with alternate arrangements of containers will be stable and do not have a propensity to tip over.
Robots have been used to load a pallet with containers. They are very versatile and can be programmed to produce almost any pattern. Robots, however, can be slow because they pick up a container and carry it to some point, then return for another. Having to move back and forth between pick up and placement points limits the speed with which the pallet can be loaded.
Machines that arrange containers into an orderly pattern and then successively stack tier upon tier to form a pallet load are also known in the art. These machines typically place the container by passing it through a series of pins, stops and pushers before ultimately getting the container to the desired location. Often times, manual adjustments must be made to change patterns. Some patterns may be difficult or impossible to form by this method.
Various types of diverting, orienting and guiding devices to direct containers for placement onto pallets are known in the prior art. See, for example, U.S. Pat. No. 5,195,627 for a pattern-forming apparatus for container palletizing. The '627 patent discloses input guide conveyor rollers which are selectively moveable between left, right or centered position for guiding containers onto one of a plurality of receiving rollers. A pattern forming zone comprising a plurality of parallel, power driven conveyors have a differential speed-control mechanism. A pusher bar pushes a layer of containers from a transfer plate onto pallets in a stacking chamber. The stacking chamber comprises a lift on which pallets are moved to receive successive tiers of containers. See also U.S. Pat. Nos. 4,002,249 and 4,901,842.
It is desirable to have a palletizing apparatus which is fast, versatile and computer programmable. It is further desirable that the palletizing apparatus have the ability to move its discharge end anywhere within a predetermined area in a horizontal plane to accommodate a wide variety of predetermined patterns.